Facsimile telegraph signal



July 6, 1948. R. J. WISE ET AL FACSIMILE TELEGRAPH SIGNAL RECORDER FiledAug. 5, 1944 FIG. I

ATTORNEY Patented July 6, 1948 FAC SIMILE TELEGRAPH SIGNAL RECORDERRaleigh J. Wise, Dunellen, and Robert D. Parrott, West New York, N. Jassignors to The Western Union Telegraph Company, New York, N. Y., a

corporation of New York Application August 5, 1944, Serial No. 548,194

8 Claims.

This invention relates to facsimile receivers or recording mechanismsadapted to record facsimile signals on a record receiving medium.

An object of the present invention is to provide a simple, efficient andrelativel cheap facsimile telegraph receiver employing a rotatable helixasthe scanning member and adapted to record received facsimile signalson a record receiving strip of the type that marks or changes color onthe passage of electrical current therethrough.

A further object of the present invention resides in the provision ofmeans for presenting the record receiving medium to the recordingmember, such as the helix, at a relatively sharp angle. This arrangementenables the successive scanned lines to be relatively close and thereproduced subject matter to have sharp and clear definition.

In facsimile recorders of the above type, variations in pressure of therecord receiving medium against the recording helix may adversely affectthe reproduction. If the paper presses against the helix with too muchpressure, the helix is apt to scuff or mechanically injure'the paper,where as if there is not sufficient pressure to establish goodelectrical contact between the paper and the helix, there may be a lossof signals and the receiver fail to produce a recording. In thisconnection it is a further object of the present invention to provide anarrangement whereby an electrosensitive record receiving medium is heldin contact with the recording helix by a substantially uniform pressureand wherein any tension on the record receiving medium employed to ad-Vance the same does not appreciably vary the pressure with which themedium engages the helix.

A further object of the invention resides in the provision of means formaintaining the record receiving medium constantly in engagement withthe recording helix in such amanner' as to'compensate for anyirregularities in the helix and to dampen movements of the recordreceiving medium supporting member that might be caused byirregularities in the helix which would tend to set up vibrationstherein.

In facsimile recorders of the above type wherein a recording helixdirectly contacts the record receiving medium, a certain amount of dirtand paper dust is apt to accumulate on the edges of the helix and ifpermitted to remain may adversely affect the recording. In thisconnection, another "object of the invention is to provide means wherebythe recording helix is cleaned by the removal of any dust or dirtthereon. The cleaning of the helix in the preferred embodiment of theinvention is arranged to occur during recording without affecting thesame.

In facsimile machines of the type wherein the facsimile signals areapplied directly to the scanning helix to cause the recording onelectrosensitive record receiving paper, a relatively strong signal isrequired to break down the electrical resistance of the paper and causea mark thereon. In this connection, a still further object of theinvention, in accordance with a modification thereof, is to provide anarrangement wherebythe received facsimile signals are effective to movean electrosensitive record receiving paper or medium into and out ofengagement with a scanning helix which may have a uniform and steadymarking potential applied thereto whereby a mark is produced on thepaper only when in contact with the helix. At all other times no markingof the paper is effected.

The above and further objects and advantages of the present inventionwill be more apparent in the following detailed description whereinreference is made to the accompanying drawings, in which:

Fig. 1 is a perspective view showing the principal components of afacsimile recording mechanism arranged in accordance with the present 1invention;

Fig. 2 is a side elevational view of certain of the elements of Fig, 1;

Fig. 3 is a side elevational view of a modified arrangement of a helixand record receiving medium supporting member;

Fig. 4 is a modification of the invention wherein the received facsimilesignals are effective to selectively move the record receiving mediuminto and out of engagement with a scanning helix which may have a steadymarking potential applied thereto;

Fig. 5 is an elevational view of the elements of Fig. 4; and

Fig. 6 is a view showing the principles of the invention as applied to apage recording facsimile machine.

Referring to Fig. 1, a motor M with shaft H has coupled thereto a helixdriving shaft l2. To the forward end of the shaft I2 is fixed a helix l3which is adapted to be continuously rotated from the electric motor M.The motor M is assumed to rotate at such a speed that the scanningperformed by the helix I3 is in synchron'ism with the scanning at thefacsimile transmitting machine and may be effected by any one of anumber of well-known synchronizing arrangements.

The record receiving medium or strip indicated generally by referencenumeral I4 employed in conjunction with the mechanism of the presentinvention may be of the type disclosed in U. S. Patent N0. 2,294,146,issued to R. J. Wise August 25, 1942. Such a record receiving medium orpaper is adapted to mark or change color on the passage of electriccurrent therethrough, and although the invention is shown in Fig. 1 asemploying a relatively narrow strip as the record receiving medium I4,the principles of the invention can equally well be applied to afacsimile recorder employing a wide recording strip or web, or of thetype that is known as a page recorder illustrated in Fig. 6.

As shown in Figs 1 and 2, the record receiving medium I4 is suppliedfrom a roll I6 supported on a spindle I], and as the strip advances fromthe roll it passes over an eccentrically or adjustably mounted rollerI3. The strip in leaving the roller I8 passes downwardly around a smallrod I9, hereinafter referred to as the printing member, platen or rod,and then back in the opposite direction to a feed wheel 2I. The strip isheld in frictional engagement with the feed wheel 2I by means of aspring-pressed roller 22 so that as the feed wheel 2! rotates the stripI4 is advanced. The feed wheel 2| is fixed to a shaft 23 which also hasfixed thereto a gear 24, Fig. 1. Engaging the gear 24 is a worm gear 26on a shaft 21 which also has a gear 28 in mesh with a second worm 29 onthe shaft l2. Through the above-described gearing arrangement the feedwheel 2| is arranged to be rotated from the shaft I2 to advance therecord receiving strip I4.

Th printing rod i9 is carried at the free ends of a pair of arms 3!which are secured at their opposite ends to a pivot rod 37.. The pivotrod 32 is supported in trunnion screws such 33 in the upper ends of amounting bracket 25. Adjustably secured to the pivot rod 32 over asleeve of resilient material 35, such as rubber, by a clamping screw 35is a counter-weight 34. The counter-weight 34 balances the arms 3| androd I9 so that any tilting of the receiver will not vary the pressure ofthe record receiving strip I4 and rod I9 against the spiral I3. A lightspring such as 30, however, may be attached to the weight 34 and/or theweight may be given a slight unbalance by adding thereto other smallweights such as 43 at an angle to produce the light normal pressurerequired between the paper and the spiral. The weight 34 bein mounted onthe resilient sleeve 35 dampens any tendency of the printing rod I9 andarms 3i to bounce or vibrate.

In order to prevent the tension developed in the strip I4 by the feedwheel H from varying the pressure with which the paper bears against thehelix I3, the feed wheel 2! and the guide roller I8 are so arranged thatthe strip, in moving to and from the printing rod I9, moves in a planesubstantially common or parallel to the plane of the rod I9 and itspivot 32. With this arrangement any tension in the strip either beforeand/or after it passes around the printing rod I9 does not tend toincrease or decrease the pressure with which the paper bears against thehelix. Accordingly, the pressure of the paper against the helix may becontrolled within rel.- atively narrow limits as determined by theamount of the Weight 40 and/or the spring 30.

The printing rod I9 is of relatively small diameter so that the paperengages the helix I3 at a relatively sharp angle, and this enables thescan ning lines effected by the helix to be relatively close togetherand extremely fine. To insure that the strip I4 follows the contour ofthe printing rod I9, a slight drag on the strip as it unwinds from thespool I6 is created by means of the weighted roller 31, Fig. 1. Theroller 31 is pivotally mounted on a screw 31a carried in the free end ofa rod 31b which is pivotally supported at its other end in the frame ofthe machine (not shown). In addition to the drag created by the roller,the eccentrically mounted guide roller I8 may be positioned so that thestrip in passing downwardly over the same engages and rubs against thestrip as it moves upwardly after passing around the printing rod I9. Therubbing of the two sections of the strip I4 together also tends toremove any foreign material or dust from the under side thereof whichmight adversely affect the recording. Dust or other foreign material onthe recording strip I4 might increase the electrical resistance of thestrip and prevent the signals from being recorded.

On the opposite side of the helix I3 from the printing rod I9 is locateda wire brush 38 pivotally supported on a. substantially vertical pin 39.The pin 39 is in turn supported in a piece of insulating material 4Icarried in the free end of an arm 42 secured at its other end to a rod43. The rod 43 is mounted in a bracket 44 and has secured thereto anoperating arm 46. The free end of the arm engages a cam 41 secured forrotation therewith. to the shaft 23. As the shaft 23 rotates in additionto causing advancement of the strip I4 it, through the cam 41 thereonand in conjunction with a spring 48 attached to the lever 46, effectsrocking of the rod 43 to swing the brush 38 into and out of engagementwith the helix I3. Thus the brush 38 periodically engaging the helix I3is effective to brush off any dirt or foreign material that mightaccumulate thereon and thereby insures that the helix is maintained inproper condition. Since the brush 38 is insulatively mounted withrespect to the other elements of the machine, there is no short circuitestablished thereby as the same contacts the helix, and the brushingaction can therefore occur during recording.

A brush 5| bears against the shaft I2 and in conjunction with aconductor 49 establishes an electrical circuit between the helix I3 andone of the conductors of the line L. The other conductor of line L isconnected by a conductor 52 to the insulatively supported bracket 25,and then by some suitable means, such as a light flexible wire 53, toone of the printing rod supporting arms 3| and the printing rod I9.Accordingly, the establishment of a potential difference between theprinting rod I9 and the helix I3 causes a mark to be produced on theelectrosensitive record receiving strip I4. The helix I3 during rotationthereof scans successive lines on the strip as the latter advances, andrecording is effected on the strip in accordance with the receivedsignals.

In Fig. 3 a modification of the recording elements is shown wherein therecord receiving strip I4 is moved toward and away from the printing rod53 in substantially horizontal paths. The strip is guided over a roller54, from whence it passes to a printing rod 53 and then to the feedwheel 56. The printing rod 53 in the modification shown in Fig. 3 issupported in substantially horizontal arms such as 51 fixed to a. shaft58 supported by suitable means (not shown). A relatively light spring59, preferably adjustable, or other suitable resilient means is providedand urges the printing rod 53 and the paper thereon against therecording helix 6| with a light normal pressure. Secured to the shaft 58over a sleeve of resilient material 62, such as rubber, is a splitcylindrical weight 63. The weight 63 is formed in two halves and clampedtogether by means of clamping screws such as 64.

The weight 63, being resiliently secured by means of the resilientsleeve 62 to the shaft 58, dampens any vibratory action that may beproduced at the printing rod 53 by irregularities in the helix 6| or anyother means and insures good contact of the recording strip M with therecord receiving helix at all times. The line signals received over theline L may be applied to the helix and to the printing rod 53 in themanner shown.

In Figs. 4 and 5 another modification of the invention is shown whereinthe line signals received over the line L are applied to anelectroresponsive device 55 including a permanent magnet 6'! and anactuating coil .68. A movable armature 69 of the electro-responsivedevice 66 is attached by means of a link H to a bail 12 which carries inthe upper end thereof a printing rod 13. The bail 12 is pivoted at itslower end, and the record receiving strip I4 is arranged to pass downaround the printing rod 13 and up through the advancing unit 14, In thisarrangement the paths of the strip M in mOVing toward and away from theprinting rod 13 are in planes substantially parallel to the plane of theprinting rod and the mounting point of the bail 12. Accordingly, anytension developed in the strip M by the advancing means 14 has little orno effect in ivoting or preventing pivoting movement of the bail 12.

In operative relation with the printing rod 13 is a helix 16 mounted ona shaft 1! and arranged to rotate in synchronism with the receivedsignals under the control of synchronizing arrangements Well known inthe art. One polarity of potential is applied through suitableelectrical connections to the helix from a battery 18 and another to theprinting rod supporting bail 12 so that, when the bail is moved to pressthe paper thereon against the helix, the battery 18 will cause a mark tobe produced on the paper. When the bail l2 moves the paper out ofcontact with the helix iii, no mark is produced on the paper, and thusthe line signals which control the movement of the bail 13 and paper Minto and out of contact with the helix cause recordings on the papercorresponding to received signals.

With the arrangement of Figs. 4 and 5, recordings on the paper strip ismay be efiected in response to signals received over the line L whichmight otherwise be of insujlicient strength to break down the electricalresistance of the strip if employed in a receiving mechanism of the typedisclosed in Figs. 1, 2 and 3, since less signal strength is required tooperate the electrosensitive device 66 than to break down the electricalresistance of the record receiving strip I4.

In Fig. 6 the principles of the invention are shown applied to arecording unit wherein a record receiving strip of considerable andgreater width than the tape disclosed in the other figures is employed.In this arrangement the same principles of operation apply, and therecord receiving medium Ma is arranged to pass over a printing rod 19 inmuch the same manner as disclosed in Figs. 2 and 4. The printing rod 19has associated therewith a helix 8| mounted on a shaft 82 whereby thehelix scans a transverse line on the record receiving web Ma for eachrevolution thereof. The printing rod l9 of Fig. 6 is supported by armssuch as 83 pivotally supported on a rod 84, and the received signals maybe applied directly to the rod 19 and helix 8| in the manner illustratedin Figs. 1 and 3, or signals may be employed to operate anelectro-responsive device such as 66 of Fig. 4 to move the printing rod19, Fig. 6, into and out of engagement with the helix 8|. In the lattercase, steady marking potential would be applied to the helix and theprinting rod 79 in the manner illustrated in Fi 4.

It will be obvious that various other modifications of the inventionother than those shown and described herein may be made withoutdeparting from the spirit or essential attributes thereof, and it isdesired, therefore, that only such limitations be placed thereon as areimposed by the prior art or are specifically set forth in the appendedclaims.

What is claimed is:

1. In a facsimile recording apparatus, means for supporting anelectrosensitive record receiving medium, a record receiving mediumadvancing means, a rotatable member with a helical ridge extendingaround the axis of rotation thereof, a rod supported on an axissubstantially parallel to the axis of rotation of said helical ridgecarrying member and movable toward and away from said ridge in a pathsubstantially radially with respect thereto at said ridge, said recordreceiving medium being arranged to pass between said rod and saidhelical ridge in moving from the source of supply thereof to saidadvancing means, means including said rod for pressing the recordreceiving medium into contact with said helical ridge whereby successivelines thereon are scanned and marked in accordance with receivedfacsimile signals by said ridge as the same rotates and said medium isadvanced, and means for guiding said medium to and from said rod, therod and the axis of support thereof and said guiding means being insubstantial alignment, said rod being between the axis of supporttherefor and said guiding means whereby the tension produced in thedirection of the length in said medium by said advancing means hassubstantially no effect in varying the pressure of said medium againstsaid ridge.

2. In a facsimile recording apparatus, means for supporting anelcctrosensitive record receiving medium, a record receiving mediumadvancing means, a rotatable member with a helix extending around the ofrotation thereof, a rod substantially parallel to the axis of rotationof said helix carrying member, said rod being supported on an axisremote therefrom and movable toward and away from said ridge in a pathsubstantially radially with respect thereto at said ridge, said recordreceiving medium being arranged to pass between said rod and helix inmoving from the source of supply thereof to said advancing means, anelectro-responsive means operative in response to received facsimilesignals to move said rod and press a section of the record receivingmedium in contact therewith against said helix, whereby as said helixrotates and said medium advances successive parallel lines on saidmedium are scanned by said helix, means including a source of potentialbetween said rod and said helix to mark said medium at the time thelatter is in contact with said helix,

means for guiding said medium to and from said rod, said guiding meansand said rod and the axis of support thereof being in substantialalignment, said rod being between the axis of support therefor and saidguiding means where by tension produced in said medium by said advancing means has substantially no efiect on the movement of said rodand medium toward and away from said helix as controlled by said fac--simile signal operated electroresponsive means.

3. In a facsimile recorder, means for supporting an electrosensitiverecord receiving strip, a rotatable member havin a spiral ridge thereon,a'printing rod for holding said strip in operative relation with said.ridge whereby successive lines thereon are d as said ridge rotates andsaid strip advances, a shaft having fixed thereto and rotatabletherewith supporting means for said rod whereby said rod is movableabout the axis of said shaft, an eccentric weight adjustably secured tosaid shaft and means including the adjustment of said weight on saidshaft relative to the printing rod supporting means for balancing saidprinting rod and said supporting means therefor.

4. In a facsimile recorder, means for support-- ing an electrosensitiverecord receiving strip, a rotatable member having a spiral ridgethereon, a printing rod for holding said strip in operative relationwith said ridge whereby successive lines thereon are scanned as saidridge rotates and said strip advances, a shaft having fixed theretosupporting means for said rod whereby said rod is movable about the axisof said shaft, an inertia member on said shaft and resiliently securedthereto for limited rotative movement relative thereto and meansincluding said inertia member for damping vibrations of said shaft androd produced by movement of said printing rod.

5. In a facsimile recorder, a rotatable member having a spiral ridgethereon and a co-operating printing rod movable about an axissubstantially parallel to the axis of rotation of said rotatable member,means for supporting an electrosensitive record receiving medium, meansfor advancmg said medium between said spiral ridge and said printingrod, an adjustable weight movable with said rod, means including saidadjustable weight for resiliently pressing said rod and said recordreceiving medium. against said spiral ridge, and means for guiding saidrecord receiving medium to and from said rod in planes such that theresolution of the tension forces in said. medium produce substantially azero component in a direction to vary pressure of said spiral ridge andsaid printing rod on said medium.

6. In a facsimile recording mechanism, means for supporting a recordreceiving web, a fixed record receiving web advancing means, a memberwith a spiral scanning ridge thereon rotatable about a fixed axis, aprinting member movable about an axis remote from and substantiallyparallel to the axis of rotation of said spiral ridge for holding saidweb in point contact with said spiral ridge, said web being loopedaround printing member and moving in substantial- 1y oppo. directionsapproaching and leaving said printing member, adjustable member forguiding said web and located between said printing member and saidadvancing means, and means including said adjustable member for varyingat least one of the paths of movement of said web toward and away fromsaid printing member whereby tension produced in said web by saidadvancing means has substantially no effect on the pressure of saidprinting member and web against said spiral. ridge.

7. In a facsimile recording mechanism, means for supporting anelectrosensitive record receiving web, a rotatable member with a spiralscanning ridge thereon, a pressure rod for pressing said web againstsaid spiral whereby the ad vancement of said Web and rotation of saidspiral eilects line-byline scanning of said web, a source of facsimilesignals applied to said pressure rod and spiral ridge for effectingrecording on said web as said scannin proceeds, a spiral cleaning memberfor removing accumulations of foreign material therefrom and means forautomatically moving said cleaning member into and out of operativerelation with said spiral during the scanning of and recording on saidweb.

8. In a facsimile recording mechanism, means for supporti anelectrosensitive record receiving web, a rotatable member with a spiralscanning ridge thereon, a pressure rod for pressing said web againstsaid spiral whereby the advancement of said web and rotation of saidspiral erlects line-by-1ine scanning of said web, a source of facsimilesignals applied to said pressure rod and said spiral ridge for effectingrecordingon said web as said scanning proceeds, an insulativelysup-ported brush member, means for periodically moving said brush memberinto engagement with said spiral, and means including said brush nemberfor removing foreign material from said spiral that may accumulatethereon incident to and during scanning of said web thereby.

RALEIGH J. NISE. ROBERT D. PARROTT.

REFERENCES CITED following are of record. in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,205,450 Wise June 25, 19402,397,535 Cooley Apr. 2, 1946

